Sunday, May 15, 2011

Junk Rigs for Non-Thinkers

Among its many flaws, The Chinese Sailing Rig - Design and Build Your Own Junk Rig by Derek Van Loan suffers from an identity crisis. It appears to be known primarily by its subtitle, and on the front cover, the subtitle is far more prominent than the main title (and on the spine, the main title doesn't appear at all). In fact, "Design and Build Your Own Junk Rig" is a more accurate title than "The Chinese Sailing Rig," but even then, it's a stretch, which I'll get to.

Van Loan says virtually nothing about the Chinese sailing rig -- nothing about its history, nothing about its current usage, next to nothing about how to sail it and, most seriously, nothing whatsoever about its pros and cons compared to Western rigs like the Marconi, gaff, etc. He seems to assume that the reader is already persuaded about the superiority of the junk rig and is ready to retrofit an existing non-junk-rigged boat with one -- and that he or she only needs to know how.

Which gets me to the promised criticism of the subtitle. Van Loan gives very little advice about how to design a junk rig, per se. Instead, he tells you how to spec a junk rig following his favorite design. Van Loan evidently has a good amount of experience playing around with the rig, and he's found a formula that works for him...and for the type of boat he likes, and the type of sailing he does, in the location where he uses it. And he expects the reader to follow his system, even if the reader's needs may differ. So he gives guidelines without explanation, such as this:

The number of battens is dependent on the sail area. Up to 200 square feet, four or five battens will suffice. Use five or six battens on a sail where the area is from 200 to 700 square feet.

As to why you should use fewer or more battens, he gives no explanation. Following his guidelines, one could use anywhere from four to six battens for a 200 square foot sail, but Van Loan doesn't give any help in deciding what is the right number within a range that contains a full 50 percent spread.

One suspects that the reason for this is that the author's understanding is entirely experiential, and that he is lacking is theoretical knowledge. His instructions for finding the center of lateral resistance consist of making a cardboard cutout of a profile of the boat's underbody and balancing it on a pin (perhaps he doesn't know how to do the math?), with this caveat:

If the rudder of the vessel is large or if the vessel has a fin keel, daggerboard, or centerboard, include about one-third its area, from its leading edge, in your underwater profile

Oh great: "about one third". Perhaps if he had explained in the first place how to calculate area, we might be able to make a start. But even so, how precise do we need to be to meet his "about" one-third guideline? Is 30% too little? How about 25%? Don't bother looking, for there's no help to be found.

By eliminating theory and math, Van Loan has attempted to make things as simple as possible, but therein lies the problem: he gives the reader not enough information upon which to make informed decisions. And then he compounds the problem by assuming specialized knowledge that the reader is unlikely to have, especially sailmaker's and rigger's terminology. The glossary is only occasionally helpful, consisting mainly of the better-known terms, and ignoring some of the more obscure ones.

Van Loan's line drawings are clear and good, and his prose is generally easy to follow. If one were to follow the book's recommendations, one would probably end up with a workable -- maybe even a very good -- rig. But that rig would be based more or less blindly on someone else's preferences, and the DIY'er would have little understanding of why it works the way it does, or how it might be improved.

"Design and Build Your Own Junk Rig" is full of editing errors, lacking in theory, and inadequate in its discussion of the author's particular preferences. For a book in its third edition, it's a notably weak effort.

5 comments:

ha, I just left a thoughtful comment but the new comment software unceremoniously discarded it when it couldn't validate my identity. Perhaps I can work up the courage to try again once I figure out the mechanics of the new and no doubt improved interface.

OK, the original comment was eaten by the comment software, I don't have the strength to re-type it in full, but here is the gist of it.1) I am curious why this particular book received what seemed like a more critical than usual review when typically you just give an overview of a book's contents. Not that I disagree with you.2) I bought the book myself about six months ago and was disappointed by it. Not that a how-to book needs riveting prose, but it is little more than a pamphlet that could be a lot more useful if someone, an editor like yourself perhaps, could work with the author and give him a sense of what a general reader with an interest in the topic and perhaps even the intention of putting a junk rig on his boat would want to know.

Wolfgang,1. Fair question. Normally, I pick out some items from the books I read that I find most interesting -- something I didn't know; something that differs from Western practice in some enlightening or surprising way. In this book, there wasn't much that I found interesting or worthy of discussion. (The special aerodynamics or other benefits of junk rigs might have made the grade, had they appeared.) Its purpose being that of a straightforward how-to, there wasn't much to say about it other than to do a critical review of how well it performs its mission, "critical" not necessarily meaning negative (although it turned out to deserve a negative one). It would be fair to ask why I selected the book to review at all -- well, it was a birthday present, and I had to do *something* with it!2. I agree that the book could use a good editor; no idea if the author or publisher would be interested though. It being in its 3rd edition, it must have already met some basic criterion of publishing success. And while I could certainly identify its needs in more detail, I don't have the expertise to fill in the missing pieces, and I'm not sure if the author does either.

I took a brief look today at "Practical Junk Rig" by Herbert George (Blondie) Hasler. I haven't read it, but it's immediately apparent that THAT is the book on the subject. Greatly detailed, minutely illustrated -- it looks quite definitive, and if you're thinking of rigging a boat junk-style with anything more than a polytarp sail, this would be your best source.

I'm going to put in a good word for Derek Van Loan, although I agree that a better title would have begun: >A< CHINESE SAILING RIG, rather than >THE< CHINESE SAILING RIG (TCSR).

As to the editorial points, this book was written to summarize notes lent, and free consultations. It was edited by his brother, typed by his wife and brought to production by a friend. All very much, I would say, in the advertised spirit of "hammer and nails" approach.

As a long time junk rig sailor, I appreciate Hasler and McLeod's PRACTICAL JUNK RIG (PJR) for its depth of analysis. It, too, however, is notably lacking in the history of Chinese vessels, nor do they attempt to analyse context of the rigs they analyze. It, too, settled on a single rig for the presentation of construction details.

Derek's geometric and physical methods for finding such nautically useful points as sail Centers of Effort, Center of Lateral Resistance, etc., are not at odds with the underlying mathematics. Nor do are they alone... I have seen the same methods presented by acclaimed experts (such as Skene's ELEMENTS OF YACHT DESIGN). They seem well in keeping with an accessible presentation.

True, his reasoning is sometimes unexplained (in several of the cases mentioned in your review), and one must accept his experience, guess, or look further afield. But other points are explained eloquently. For example, his to-the-point discussion of ONE MAST OR TWO? is still among the best I've seen.

As a long time, DIY junk sailor - and one not at all intimidated by the mathematical aspects - I still refer as often to TCSR as to PJR. Given that they are still the only two books of note on the design and construction of junk rigs of any stripe, that's high praise!

Can it be improved? Of course... what can't? But is it useful? Speaking for my self, very much so. Is it worth the price? Let's put it this way... when I bought it, years ago, and still today, it's about the price of admittance to the latest Hollywood must-see.

While I've never built a rig to Derek's sail planform (Dave Mallory's, actually), I'd say I got my money back in spades!

Dave Z

PS. Ditto BEUHLER'S BACKYARD BOATBUILDING!

PSS. In a recent development of the western junk sail - Slieve McGalliard's Split Junk Rig - he utilizes some of the low yard angle concepts presented in TCSR, which help tame stress loading throughout the sail and thereby reducing standing and running rigging. Not bad!